This application claims the priority of German application 199 25 003.0, filed May 31, 1999, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a brake disk made of a fiber-reinforced material including two assembled friction rings provided with ribs at interior sides and which are supported with respect to one another along at least a portion of the ribs.
German Patent Document DE 44 45 226 A1 relates to a brake disk for disk brakes which consists of a material of the carbon group. According to one embodiment, the brake disk is produced in halves such that each of its radial ribs is molded to one friction ring. Connection of the friction rings is to take place by way of correspondingly constructed faces of the ribs.
With respect to this prior art, it is an object of the invention to provide a suitable shaping of such faces.
According to the invention, this object is achieved by providing portions of the ribs used for support with coupling faces which correspond on a face side and which cause a coupling of the friction rings exactly in one rotating direction. The coupling faces are arranged in an alternating manner. It is suggested that faces used as coupling faces be constructed such that coupling of the friction rings is caused exactly in one rotating direction and such that the coupling faces are arranged in an alternating manner. The coupling of the friction rings in exactly one rotating direction means, in this context, that, in addition to the axial support, the ribs are connected with one another, for example, only during a rotation to the right of one friction ring with respect to the other friction ring; during a rotation to the left, the ribs would detach from one another. Since the the coupling faces are arranged alternately on the ribs, the two fiction rings are coupled with one another in both directions. The special advantage of this arrangement is that coupling faces acting only in one rotating direction can be produced particularly easily. In particular, with the materials used, it is possible to produce such coupling faces already in the molding process of the friction rings without any additional reworking. The coupling faces can preferably be constructed as slanted plane faces or so that each face is stepped on one side.
Advantageous further developments of the invention are also reflected in the claims.
It is suggested to provide, in addition to the coupling faces, support faces without any coupling of the friction rings in the rotating direction. The support faces preferably may have a plane construction. Since only a single production measurement, specifically the height of the support forces, is of considerable importance in this case, their production in a molding process or machining process is much simpler than the production of coupling faces. The number of coupling faces, therefore, can be reduced to that required for transmitting a torque from one friction ring to the other friction ring.
While slanted faces are easier to produce, stepped faces have the advantage that, here, forces introduced in the axial direction, such as forces generated by the brake linings, cause no reaction forces in the circumferential direction. In connection with a molding process, it may, in addition, be advantageous to construct the coupling faces as slanted wavy faces. Such faces are well suited for a molding process because they have no sharp edges. Simultaneously, their profiles can be designed such that forces in the axial direction can also be transmitted without generating any reaction forces in the circumferential direction.
The above-mentioned coupling face constructions are suitable for ribs which are arranged in a radial, tangential manner and also for ribs which are arranged in an involute curved manner. Furthermore, in addition to ribs with coupling faces and ribs with support faces, half-ribs can be provided such that each half-rib is arranged opposite one another on the interior side of the friction rings. In the cooling ducts formed by the ribs with the coupling faces and the support faces between the friction rings, these half-ribs provide additional surfaces for improving the heat transfer from the brake disk to the cooling air flowing through it.
For a further improvement of wet-braking action and heat transfer to the cooling air, bores can be provided in the friction ring. These bores can preferably already be made during the molding process of the friction rings.
To produce the brake disk, a fixing of the two friction rings in the axial direction is sufficient because the friction rings are coupled with one another in the rotating direction by the construction of the coupling faces under the effect of the tension forces applied during a braking operation. Care must only be taken to transmit the torques generated during the braking operation by way of one or both friction rings to a brake pot or similar device.
The invention will now be explained in detail in connection with embodiments illustrated in the figures.